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ISIS blames Obama for Sotloff beheading

The executioner appears to be the same person. The location of the two killings also appears to be similar.

Neumann suspects they took place in or around the Syrian city of Raqqa, one of the safest areas for ISIS, which calls itself the Islamic State.

"It's titled 'A Second Message to America,' and it basically contains exactly the same message," Neumann said about the Sotloff video, which was posted Tuesday.

A video of Foley's execution was released last month.

The executioner

Sotloff's apparent executioner speaks in what sounds like the same British accent as the man who purportedly killed Foley.

He's dressed identically in both videos, head to toe in black, with a face mask and combat boots. He appears to be of similar build and height. He waves a knife in his left hand, as did the militant in the video of Foley's death.

And then, there are his actual words.

"I'm back, Obama, and I'm back because of your arrogant foreign policy towards the Islamic State," the executioner says in the second video. "Just as your missiles continue to strike our people, our knife will continue to strike the necks of your people."

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The administration does not want to speculate on specifics of the video until those questions can answered, a senior official told reporters.

Paul Ginsberg, a forensic audio and video expert, said analysts will comb through every inch of the video, "analyzing the electronic impulses, the audio, the video, the speech, voice identification, the geography -- for whatever information it can provide -- as well as the production techniques."

U.S. analysts have said it's not possible to know from the first video who beheaded Foley because the entire slaying is not shown. A man moves a knife across Foley's neck, then the picture fades to black.

One forensics expert has raised the issue that there appear to be two militants in the video. The second militant appears on the video after an obvious edit.

"There's definitely a change of actor," said Ross Patel, the forensics expert. "There are noticeable -- there are subtle -- but there are also noticeable changes in their build, their physical appearance."

The man who speaks, holds a knife in one of his hands. It looks to be a different knife than the one that was left next to Foley's body.

Also, the dimensions and style of the knives are slightly different, Patel said.

In the Sotloff video, the picture fades to black immediately before and after the start of the beheading so, again, it's not immediately clear whether the man speaking is the same man who then killed the journalist.